Push type reversing valve



Aug. 12, 1952 w, p PERM 2,606 736 PUSH TYPE REVERSING VALVE Filed Aug. '7, 1947 William D. :rm

224/14. fim/vvzA/twkg BTTOmaY-J Patented Aug. 12, 1952 IUNITEDZSTATES PATENT OFFICE 'William. P. Ferm, Grand Haven, Mich., assignor to Keller Tool Company, Grand Haven, Mich., a; corporation of Michigan Application August 7, 1947,.Seria1No. 766,929

f 3 Claims.

The. present invention relates reversible rotary air motors, and more. particularly to a novel reversing valve mechanism for controlling the operation of such motors.

A general object of the invention is to provide an effectual valvemechanism ior pressure iiuid actuatedrotary motors which is exceedingly simple in construction, which may be'manufactured economically and which is, capable of being quickly and easily manipulated.

Another object is to provide for the control of the direction'of rotation of such motors solely by means of a-single valve deviceof the shiftable plunger type.

The objects of the invention thus. generally set forth, together with other and ancillary advantages, are attained by the construction. and arrangement shown by way of"illustration in the accompanying drawings, in which:

Figure 1 is a fragmentary side elevation partly in section of a portable tool incorporating. the present invention.

Fig. 2 is a sectional View of the instant valve mechanism on an enlarged scale. and showing the valve in position for forward operation of the motor. i I

Fig. 3 is a sectional viewsimilar to Fig. .2 but showing the valve mechanism in pos'iti'onlior reverse operation of the motor.

Fig. 4 is a section takenks'ubstanti'ally along the line 3-4 in Fig. 2. j I

Fig. 5 is a section taken substantially along the line 5-5 in Fig. 2.

Fig. 6 is an exploded perspective view of the valve mechanism.

While 'the'invention is susceptible of various modificationsand alternative constructions, there is shown in the drawings and will herein be described in detail the preferred embodiment, but it is to be understood that it is not thereby intended to limit the invention to the form disclosed, but it is intended tocover all modifications and alternative. constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Reversible pressure fluid actuated rotary motors commonly include a cylinder having a bore therein within which is eccentrically disposed a rotor having a plurality of slidablevanes for cooperation with the bore wall. In the operation of such motors, air is admitted to and exhausted from the motor cylinder through the medium of conventional inlet and exhaust ports. Additionally, provision is made for the escape of air trapped ahead of the rotor vanes between the rotor and the bore wall adjacent the point of con act b twe n eserarts. My invention especially concerns the provision of a reversing valve mechanism of a simple character controlling the admission of air under pressure to the motor and the release of the aforesaid trapped air. Inasmuch as the motor per se forms no part of the invention, it is deemed unnecessary to illustrate and describe the same in detail, reference being made to Patent No. 2,159,232 issued May 23, 1939 to Ernest H. Shaffior a full disclosure of a motor oithe type in question.

Referring now to-Fig. 1 of the drawings. my invention has been shown for purposes of i1lustration as embodied in a portable pneumatic tool comprising a sectional casing including a rear section H] in the form of a pistol type handle, and a cylinder section H forming a housing for a rotary vane type motor 12. Air is supplied to inlet passages Ila of the motor (only one of which is shown) from any suitable source as byway of a fitting 13 in one end of the handle section ID of the tool, and the 'flow of air to the motor .isunder the joint control of a manually operable throttle valve [.4 and a reversing valve ,20.

The throttle value may .be of conventional construction. As shown, it comprises a sleeve I 5 inserted into a bore 16 and aplunger valve .Ll' biased by. a spring l8 into closed position. The bore [6 communicates with the fitting l3, and the plunger 11 is, arranged for actuation, by means of a lever 19, into open position against the action of spring I8. 'Upon movement into open position, air pressure passes through a duct 2| leading to the reversing valve 2i).

The improved reversing yamegze is disposed in a bore 20a .in the rear casing section it) and comprises a two-position plunger 22 slidable in a ported sleeve '23 and operative in its respective positions to. admit air under pressure to either of two passages 24 vand 2'5 and at the same time to permit the escape of trapped air from the motor. The valve plunger zlprovides an inlet chamber 26 of such construction as'to communicate with the supply duct 2! in either-position of the plunger while connecting with one or the other of the passages 25 and 25 depending on the position of the plunger. In the present instance, the inlet chamber'z s is in the form of a transverse annular groove 21 adjacent the lower end of :the plunger 22 and an axial channel 28 connecting at all times with the supply .diuct 2| through a port .29 in the sleeve 23. .So that pressure fluid can be selectivelysupplied to either of the passages :241or 2:5, the sleeve 2:3 :is providedwith axially spaced ports '30 and #31 registering with the passages, the groove 27 in the plunger being carried by movement of the plunger into register with either of the ports 30 or 3|. The plunger is biased into its uppermost position, which is normally forward running position, by a spring 32 interposed between the plunger and the bottom of the bore 26a.

Fluid trapped in the motor after normal exhaust is permitted to escape through that inlet passage not being used to supply pressure fluid to the motor. In the present instance, referring particularly to Fig. 2, this escaping fluid flows through the passage 25 to the reversing valve 20 where it is received in a secondary exhaust chamber 33. As herein shown, the secondary exhaust chamber is defined by the bottom of the plunger 22, the lower end of the sleeve 23 and the bottom of the bore 20a. From this chamber the fluid escapes to the atmosphere by way of passages 34 and 35.

In Fig. 3, the reversing valve mechanism is shown in position for reversecondition of operation of the motor. In this position, the groove 2'! registers with port 3| to supply pressure fluid to the passage 25. Escape of trapped fluid from the motor in this condition of operation is by way of the other passage 24 and its port 33 to the secondary exhaust chamber 33. To afford communication between the port 30 and the secondary exhaust chamber, a transverse slot 36 is provided in the plunger 22 and this slot intersects an axial bore 31 in the plunger 22 the lower end of which opens into the secondary exhaust chamber 33.

Provision is made to retain the plunger in position for reverse condition of operation of the motor without the necessity of itsbeing held down by the operator. To this end, the plunger is provided with a radially extending pin 38 which is guidingly received in a bayonet slot 39. Thus, when the plunger is forced downwardly against the action of the spring 32 it is held in such position upon a slight rotation thereof by the pin 38 engaging the transverse portion of the slot 39. Accordingly, the axial channel 28 and the port 29, groove 21 and the port. 3|, and the slot 36 and the port 30 are of suflicient transverse dimension that communication therebetween is unhindered upon such slight rotation of the plunger. L i

For convenience the plunger 22 is provided at its upper end with a thumb button 40 threaded into a bore 4|.

The instant construction has the particular advantage of permitting preassembly of the valve to the end that it can be inserted as a unit in the bore 20a in the rear casing section l0, thereby facilitating manufacture of the tool while at the same time preventing its removal and thereby preventing tampering and possible misalignment of ports and passages. Thus the plunger 22 with the thumb button 40 secured thereon is inserted in the sleeve 23. With the recess in the plunger 22 for the reception of the pin 38 aligned with the bayonet slot 39, the pin 38 is pressed into the recess. Thereafter the spring 32 is put in place in the bore 31, and the now fully assembled valve is inserted in the bore 20a so that the ports 29, 30 and 3| are aligned with the ends of the passages 2|, 24 and 25, respectively, the sleeve 23 being pressed into the bore 20 until its outer end comes flush with the portion of the casing I0 surrounding the bore.

Summarizing, pressure fluid is supplied from the throttle valve M to the inlet chamber of the reversing valve mechanism 20 by way of the duct 2| and the port 29. When the reversing valve mechanism is in its normal position, that for forward operation of the motor, pressure fluid is supplied from the inlet chamber 26 to the passage 24 by way of the port 30. Fluid trapped in the motor after normal exhaust escapes through the passage 25 and the port 3| directly to the secondary exhaust chamber 33 and thence to the atmosphere through the passages 34 and 35.

Conversely when the valve is in its lowermost position, that for reverse operation of the motor, pressure fluid is supplied from the inlet chamber 26 to the passage 25 by way of the port 3|. Trapped fluid escapes from the motor by way of the passage 24', the port 30, the slot 36 and the bore 31 to'the secondary exhaust chamber 33 and thence to the atmosphere as before.

From the foregoing therefore, it can be seen that a reversing valve mechanism constructed in accordance with the present invention is of exceedingly simple construction, can be manufactured economically, is capable ofquick and easy manipulation, and solely by means of which admission of pressure fluid to and in part the exhaust from the motor is controlled and in so doing controlling the direction of operation thereof.

I claim as my invention:

1. A reversing valve mechanism for use with a reversible pressure fluid. actuated rotary motor having a pair of inlet passages, comprising, in combination, a sleeve having an inlet port communicating with a source of pressure fluid and a pair of ports for communicating respectively with said motor inlet passages, a plunger within said sleeve having an annular groove adjacent the inner end thereof and a longitudinally disposed relieved portion in one side thereof intersecting said groove defining an inlet chamber having continuous communication with said inlet port, said plunger further having an axial bore therein and a slot disposed intermediate its ends peripherally spaced from said relieved portion and intersecting said bore, said plunger and said sleeve together defining an exhaust chamber into which said bore opens, said plunger being shiftable into alternative positions whereby said groove may be brought into register with the ports of said pair selectively, and said slot registering with one of said pair of ports when the other communicates with said groove.

2. In a pressure fluid actuated tool including a reversible rotary motor and a casing enclosing the motor having a bore therein and a pair of inlet passages for the motor intersecting said bore, a reversing valve mechanism comprising, in combination, a sleeve adapted to be press fitted in said bore and having an inlet port for communication with a pressure fluid source and a pair of ports for communication with said inlet passages, and also having a bayonet slot therein, a plunger having a peripheral groove adjacent one end thereof defining an inlet chamber having continuous communication with said inlet port, said plunger being adapted for axial movement within said sleeve between two positions to register said groove alternatively with the ports of said pair and having an axial bore therein adapted to communicate at one end with the atmosphere and with one of said pair of ports at the other end thereof intermediate the ends of said plunger in one of its two positions, a spring adapted to be received in said plunger bore and seat in said in bore for biasing said plunger toward one of its said positions, and a pin supported by said plunger for reception in said bayonet slot to maintain the plunger in the other of its positions against the action of said spring, said sleeve, plunger, pin and spring permitting of preassembly prior to insertion of the valve in said casin bore.

3. A reversing valve mechanism for use with a reversible pressure fluid actuated motor having a pair of inlet passages, said valve mechanism comprising, in combination, a sleeve having an inlet port for communication with a source of pressure fluid and a pair of longitudinally spaced ports for communicating respectively with the mot-or inlet passages, a plunger having a peripheral groove adjacent one end thereof and having an axial bore therein communicating at one end with the atmosphere, said plunger also having a transverse slot therein intermediate its ends and communicating with said bore and a relieved por tion in one side thereof peripherally spaced from said slot and intersecting said groove, said slot and groove being longitudinally spaced to corre spond to the spacing of the ports of said pair, said relieved portion extending longitudinally of said plunger from the outer transverse wall of said roove to a point determined by the opposite transverse wall of said slot so as to define with said groove an inlet chamber having continuous communication with said inlet port, said plunger being shiftable axially within said sleeve between two positions to register said groove alternately with the ports of said pair.

WILLIAM P. FERM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

